babel-core vs core-js: What are the differences?

Introduction

In the world of JavaScript, both babel-core and core-js play significant roles in enhancing its functionality and compatibility across different browsers. While there might exist some similarities between these two libraries, there are key differences that set them apart. In this article, we will explore six significant dissimilarities.

1. Babel-core: Babel-core is a JavaScript compiler that is mainly used for transpiling ES6+ (ECMAScript 2015 and later) code into backward-compatible versions of JavaScript that can run on older browsers. It primarily focuses on transforming the syntax and ensuring that the code adheres to the target environment's specifications.

2. Core-js: On the other hand, core-js is a modular library that provides polyfills for various JavaScript features and APIs. Unlike Babel, core-js does not primarily deal with transforming the syntax but rather delivers missing or not fully implemented features to older browsers. It aims to ensure that JavaScript code can run consistently across different browser versions.

3. Babel-core transforms syntax: Babel-core enables developers to use modern JavaScript syntax features, such as arrow functions, destructuring, and spread operators, which are not natively supported by older versions of JavaScript engines. It transforms such syntax into an equivalent code that can be understood by those engines.

4. Core-js provides polyfills: Core-js, however, focuses on providing polyfills or shims for JavaScript features, APIs, and methods that might not be supported by older browsers. These polyfills help bridge the gap between modern coding practices and older browser support, allowing developers to use new functionality while ensuring compatibility.

5. Babel-core has a broader scope: Babel-core not only transforms syntax but can also be used for handling additional functionalities such as JSX transformation, TypeScript compilation, and code minification. It serves as a complete tool for modern JavaScript development workflow.

6. Core-js is modular: Core-js takes an approach of providing individual modules for different JavaScript features and APIs, allowing developers to selectively include only the functionality they need. This modular design helps in reducing unnecessary code size and optimizing the performance of the final bundled JavaScript file.

In summary, Babel-core mainly focuses on syntax transformation and broader development workflow, ensuring backward compatibility, while core-js provides polyfills for missing or not fully supported JavaScript features and APIs, enabling developers to use modern functionality across different browser versions efficiently.